Sister
by irllucina
Summary: A retelling of Undertale tying up some loose ends with an OC of mine. It's a bit poetic at first but it'll get less like that as I continue, so don't worry! Implied OC x some people but eh.
1. Beginning

_hello! this a prose thingie i wrote. its about my undertale oc. her name is sis and she's frisk's older sister. you'll figure out what she goes through in a bit. let me know what you think!_

* * *

She fell first.

It was a stupid dare, but the kids she went to school with said she could do it. And she wanted to finally have a place for herself and them to go when Mom and Dad… They needed another place to stay, and a friend from school was just the trick.

She should've known it was just a way for them to laugh at her.

She awoke on a bed of golden flowers, and she knew she must've been out for a while from the indent in them. She rose, trying to get her bearings, remember what had happened. When that was all set, she knew she messed up. She needed to get home. She didn't want them dealing with their parents alone. She'd made a promise... she'd protect them.

She encountered a living golden flower, Flowey, and he nearly tricked her into handing her life to him. She'd run straight into his "friendliness pellets" and hadn't done a thing afterward, simply started to cry and waited for the end.

Until she was saved.

* * *

Toriel was her name, and she was an old, kindly goat-woman. She seemed to adopt the 18-year-old girl immediately, and seemed intent on allowing her to live here. As new and welcomed the kindness and love Toriel provided her, they weren't here. She needed to keep them safe.

She needed to protect them better than she did before.

She didn't kill anyone, and talked every monster down. She bought a spider doughnut and cider. She made friends with Napstablook, and promised to meet them at their snail farm, though it was empty and she only said it so he didn't feel bad.

Toriel made her cinnamon-butterscotch pie. She ate a piece after taking a nap. And as attractive as the idea of living with Toriel and having a proper mother, one that didn't ignore her children and punish them for awfully small things, they weren't here. She needed to go back. So she begged Toriel to show her the way out, and she did with the empty threat of destroying the only way out of the ruins.

She couldn't stop the fight. But she spared her, with enough begging and pleading, she spared Toriel. She gave her one last hug, holding back her tears and agreeing to not come back. And she stepped out of the ruins.

* * *

She was being followed. The stick breaking behind her was more than enough to know there was something tailing her. She'd be dead in a few seconds, they would be alone please God let me live I'm sorry I couldn't protect them I'm sorry let me go home I need to protect Frisk.

She stopped at a bridge, and the one following her asked if she knew how to greet a new pal. They told her to shake their hand.

Fearing her life, she did.

At the fart noise that pierced the air, her eyes widened, then she lost her breath as she laughed, tears leaking out of her eyes, and her laughs devolved into sobs. She fell to her knees, covering her face as she wept for Toriel, Frisk, for being so alone, and the skeleton that had been following her simply gave her a few encouraging pats, then lent her his coat.

His brother wasn't too keen on capturing a human like this.

* * *

She stayed with the skeleton brothers for a few days, crashing on their couch. A few days after her first night, she woke up with an odd feeling. Something big was going to happen today. So she asked Papyrus and Sans (those were their names) if she could come with them to scout for humans. They allowed it, but she had to stay close to town.

So she did.

And when she finally saw them in her vision, she smiled bigger than she had since she fell down here.

Frisk.

She knelt and opened her arms for a hug, and Frisk ran to her immediately.

She was leaving Snowdin tomorrow. They were going home. Frisk wanted to go home.

* * *

They departed for Waterfall hand-in-hand, and she promised Frisk she'd protect them.

Despite the anxiety bubbling up from running from Undyne. They got to see Napstablook's snail farm. They found Temmie Village. They took the Riverperson's boat and visited Papyrus from time to time, but mostly the two stayed determined.

Monster Kid was pretty cute, even if they kept falling on their face. They ran from Undyne all the way to Hotland, then went back to hang out with her with Papyrus. A flaming house and a panic attack from her later they were all friends now.

She'd never felt happier in her life than she had the past few days.

They met Alphys and Mettaton, and she wasn't sure what was really up there for them anyway.

* * *

Muffet was interesting. A spider donut and an anxiety attack was all it took for her to spare them. Frisk comforted their big sister on the way out the spider's lair, and she felt bad she couldn't protect them again. She needed to do better.

* * *

Fighting a killer celebrity robot was interesting, but it all had to end one day. One body transformation later, a posing contest, (she wouldn't disclose where she learned all her poses, nor where she learned to "Wry" like that) and a talk with Alphys led to the elevator up to New Home.

They met Asgore face to face and she could tell he didn't want to fight them. He told them he needed only one soul. Frisk's grip tightened in her hand and they shook their head. He'd kill them both or neither at all.

They were always so optimistic. She wished she could be like them.

* * *

She could barely breathe. Panic gripped her in addition to her sadness. What was she going to do? She was so lonely without them already. How would she live the rest of her life like this? Asgore had knelt down, apologizing and telling her this was a sacrifice that needed to be made.

They were interrupted by a small creature. Black fur, white rings around its legs, rabbit-like ears, and on its forehead. Blood red eyes. It told her it could give her the power to go back. To LOAD. All it needed...

Was her soul.

She accepted immediately. She could go back. She needed to save them.

It took her soul; a red, slightly darker than Frisk's, and she reached for her new power.

Time travel felt weird.

* * *

She awoke in the skeleton brothers' house, and she had a feeling this wasn't going to be an ordinary day.

Something big was going to happen.

* * *

 _well, that's all! you'll get more of an explanation in other chapters. there'll be a few more prose chapters then itll turn into a bigger more descriptive story if that makes sense. lmk what u think!_


	2. Sloth, Patience, Diligence

_hi everyone! it's been about a month, sorry about that! ive been swamped with schoolwork i missed during my four-day absence when i had stitches. it wasn't fun but im much better now and it's almost break time so! that'll be fun! anyway let me know what you think! im not too sure if i like this chapter but whatever! thanks for reading!_

* * *

 **Sloth, Diligence, Patience**

She glanced down at her palm. A loose chain around her neck held a small, heart-shaped charm. She hid it beneath her sweatshirt, playing with the device around her wrist, running her index finger over the similarly heart-shaped indent. This was how she could LOAD now. That was what it said.

* * *

The creature was named Charos. It was a CORE Custodian. As the name implies, it watched over the CORE and ensured it continued to function properly. Charos described it as one of the most important types in its race, the Faces. She had plenty of questions, but they could wait.

For now, she was grateful for the second chance.

She'd practically jumped off of the skeleton brother's couch with unfounded enthusiasm and just about scared the wits out of Papyrus. The taste of his spaghetti for breakfast could do nothing to deter her from the hope she felt.

She could save them.

Frisk.

* * *

She knew she had to be at least a little subtle. She couldn't let off that she knew more than she should. Charos stuck around to make sure she didn't mess up, and she was happy for the company.

She nearly cried with joy at seeing her sibling walking through Snowdin.

* * *

There was no rush this time.

She wanted time to wipe the image of blue and purple stripes stained with red.

* * *

Frisk was mesmerized by Charos. Small and cat-like, they found it cute (it didn't help that their parents never wanted to see pets in the house). Charos allowed them to hold him as they walked through the Underground together.

Nothing was surprising to her anymore, and she had to catch herself multiple times in order to keep up the act.

If Frisk was comfier with her being as foreign to this place as them, so be it.

* * *

Befriending people she had already befriended was boring. Leaving her friends behind was tougher.

She found a toy knife in the garbage dump, and pocketed it.

Just in case.

* * *

They killed a Vulkin by accident, and she pretended not to see Charos' eyes glint.

* * *

Mettaton's house explained so much.

Frisk killed him anyway.

* * *

Sans looked directly at her as he spoke of the LOVE they'd gained.

* * *

She'd failed again. She was too slow, there was a fight, they had gone ahead. It was stupid, so stupid now. She didn't even remember what they were fighting about.

Asgore had smashed her LOAD-er. The heart laid in small fragments of what it once was before her.

She was stuck.

There was no going back.

Just like everything else she tried to fix, she made it even worse before she even started.

Tears formed in her eyes, but she blinked them away. She didn't care anymore. The whole world could have rot at that instant and she wouldn't have cared.

It wasn't even worth trying.

Everything she touched, she ruined.

Charos stood before her.

 _You not only have the ability to LOAD. You can PAUSE as well._

Asgore looked still as a statue, he wasn't even breathing. Frisk was already dead. Frozen in time there was no difference.

 _Think on it. I'll take your soul once more if you wish._

Hope pooled into her heart once more. She was so gullible. She nodded slowly, solemnly. Might as well, right? If she screwed up again maybe she could just throw down her soul for Asgore to take like cookies and milk for Santa every Christmas Eve.

Her soul was blue this time. A light blue, almost aqua. She wondered if that meant anything.

She still wasn't used to time travel.

* * *

She awoke back on the skeleton brothers' couch. Papyrus was making spaghetti for breakfast, and Sans looked at her with the usual smile and a wink as he walked downstairs.

Just like last time.

She reflexively shoved her hands in her sweatshirt pockets as she stood awkwardly, trying to think of the words she'd said the first two times she'd tried this. Her hands found the toy knife.

Her eyes widened. No, she couldn't... but if it came to it...

She'd do what she had to.

For Frisk.

* * *

 _welp that about wraps up chapter 2! im gonna try and write a little more tomorrow but for now it's really late so! again sorry about the delay and let me know what you think! predictions are absolutely a-okay too by the way!_


End file.
